And ezra t



(No Model.)

T. A. EDISON & E. T. GILLILAND.

. hAILWAY SIGNALING. v No. 4,830. Patented June 19, 1888.

wires STATES PATENT O FICE.

'rmmAs A. nurses, or LLEWELLYN PARK, NEW JERSEY, AND EZRA T.-

GTTLTLAND, or new roan. N. Y.

RAILWAY SIGNALING.

SPECIFICATION forming part of Letters Patent No. 384,830, dated June 19, J 888. I

Application filed November 19, 18%. Serial No. 220,115. (No model.) i

in (All when it may concern..- j

3c itknown that; we, THOMAS A. EDISON, of Llewellyn Pa k, in the county of Essex and State of New Jersey, and EZRA 'l. G ILLILAND, ot' the city, county, and Stateol' New York, have invented a certain new'and useful Improvement in Systems of ltailway Signaling, (Case No. 681,) of \Vllll'll the following is a specification.

Our inventhiu relates to signaling systems for communicating between stations and moving trains by induction from the telegraphwires to the roots of the 'cars. In such a sys tern we prefer to employ as transmitters vibrators operated by keys,by which'signals-arc sent upon the line, and as receivers telephonein the car and station being shown diagrammatically. Fig.2 is a larger diagram of the preferred arrangement of circuits for eithera car or station; Fig. 3, a similar diagram of a modified arrangement of circuits, and Fig.4 a view of the vibrator which we prefer to use.

One feature of our invention is the dividing of the transmitting induction-coil--that is, using two or more small coils instead of one large one. Heretofore we have placedin each station or car a single induction-coil having in its primary circuit a key and a vibrator, while its secondary circuit was connected in one direction with the earth,and in the other, at the station, through condensers to the tele graph-wires, and on the car with the metal roof thereof. By our present invention we employ two or more ind'nction coils, prefer ably having their primary coils in series and their secondary coils in multiple are, though they may be otherwise connected, as will be presently explaincdl Referring to the drawings, A represents a station, and B a car, each provided with signal transmitting and receiving apparatus em-. bodying our invention. In the station such apparatus is connected by wires a a, through condensers I) I), with the ordinary telegraphwires, 0 c,which extend along the track. In the car the apparatus is connected by. wire (1 with the metal roof of the car or with metal strips placed thereon. ratus is provided with a switch, 6, by which either the receiving or transmitting apparatus 'is connected in circuit. I

As is now well understood, the vibrations communicated to the telegraph-wires by the transmitter at the station are transmitted by induction to the roof of the ear and to the receiving apparatus thercin,while the vibrations Each signaling appatransmitted from the car induce vibrations stitutes another feature of our invention inpnrsuance of the general object of increasing the rapidity and distinctness of the vibrations; It consists of a diaphragm, F, like a telephonediaphragmand preferably'of' metal, secured rigidly at i s edges, and having atits center, which is immediately in front of the core of the induction-coil D, a contact-piece,f, which makes and breaks circuit as the diaphragm is moved by the attraction of said core with a stationary contact-point, g. The secondaries of the induction-coils are connected in multiple are, as shown, between-switch e and the earth, the. groundconnection being made in the car by a connection with the wheels thereof.

The receiving apparatus is a telephoneceiver, G, in circuit between switch e ground.

\Vheu the key E is depressed,th e diaph ra cuits is shown.

Diaphragms used as vibrators give more rapid, "clear, and distinct vibrations than have heretofore been produced by the use of reeds or pivoted or other vibrators.

The division of the induction-coils has a similar efi'eet,sincc the smaller inductioneoils act with much greater rapidity than large ones.

In Fig. 3 a different arrangement of cir- Here the battery is divided into two parts in multiple arc to each other, and each in series with the primary of one of the inductions,which also are in multiple arc to each other. The vibrator is common to both primary circuits. and a double key, H, is employed, which aii'ects the two primary circuits alike and simultaneously.

. Each induction-coil primary is shunted by a condenser, Lwhich we find also serves to increase the clearness of the vibrations.

What we claim is- 1. In transmitting apparatus for induction railway signaling, the combination, with two or more induction-coils having their secondary circuits connected to line, of a battery, 21 key, and a vibrator, all located in the primary circuits of the two or; more induction-coils, substantiaily as set forth.

2. In transmitting apparatus for induction railway signaling, the combination,with an induration-coil having its secondary circuit connected to line, of a battery, a key in the primary circuit of such induction-coil, and adiaphragm-vibrator also located in such primary circuit, the diaphragm being located nearthe end of the core of the.induction-coil and being attracted thereby, substantially as set forth.

. 3. In transmitting apparatusjor induction railway signaling, the combiriatiomwith two or more induction-coils having, their secondary circuits connected to line, of a battery,and a key in the primary circuits of such induction-coils, and a diaphragm-vibrator also located in the primary circuits of both coils,the diaphragm being located opposite the core of one coil and being attracted thereby, substantially as set forth.

4. In transmitting apparatus for induction ,railway signaling, the combination, with the transmitting battery and key, of a diaphragmvibrator in circuit therewith, substantially a set forth.

This specification signed and witnessed this 24th day of November, 1886.

THOS. A. EDISON. EZRA I. GILLILAND. Witnesses:

WM. PELZER, E. C. ROWLAND. 

